J. P. Morgan & Co., the nation's fifth-largest bank holding-company, said yesterday that its first-quarter profit jumped 42.1 percent from a year ago. The improvement resulted mainly from an 89.3 percent increase in noninterest operating income.

Meanwhile, General Electric Co., Whirlpool Corp., Celanese Corp. and Walgreen Co. reported higher quarterly earnings.

J. P. Morgan & Co., Morgan Guaranty Trust Co.'s parent based in New York, said its net income for the three months that ended March 31 came to $233.9 million ($2.56 a share), compared with $164.6 million ($1.85) in the same period last year.

Increases were reported in all areas of noninterest income, especially from foreign exchange and other trading. The company said it also had substantial net gains from the sale of investment securities.

*General Electric Co. reported first-quarter net income of $537 million, a 5 percent increase from the same period a year ago, on 5 percent lower sales of $5.88 billion.

In the first quarter of 1985, GE earned $511 million ($1.18) on $6.20 billion in sales; last year's per-share earnings were $1.12 in the comparable period.

*Whirlpool Corp. announced its net income rose 27 percent and sales increased 10 percent in the first quarter of 1986, compared with the corresponding period last year.

Some of the gains reflected acquisitions of two kitchen appliance and hardware companies, according to the firm, which is based in Michigan.

For the first quarter, net income for the appliance maker totaled almost $49.3 million ($1.34), up from $38.9 million ($1.06) the year before.

*Celanese Corp.'s earnings for the first quarter of 1986 jumped 42 percent to $51 million, despite lower sales, according to John D. Macomber, chairman, president and chief executive officer.

He attributed the earnings increase to the declining value of the dollar, greater efficiency and lower oil prices, which made the company's chemicals, fibers and specialty products cheaper to make.

The company, which is based in New York, said its net income for the three-month period that ended March 31 was $4.13 a share.

*Walgreen Co., a drugstore chain based in Illinois, reported higher income and sales for the second quarter and first six months of fiscal 1986.

Net earnings for quarter ended Feb. 28 were up 15 percent to $35.6 million (58 cents), compared with $31 million (51 cents) last year, Walgreen said.